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mm/vfs: revalidate page->mapping in do_generic_file_read()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / nilfs2 / segment.c
blob687d090cea341fea2f0cf88ac9b4b41e36dcf957
1 /*
2 * segment.c - NILFS segment constructor.
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
21 *
22 */
23
24 #include <linux/pagemap.h>
25 #include <linux/buffer_head.h>
26 #include <linux/writeback.h>
27 #include <linux/bio.h>
28 #include <linux/completion.h>
29 #include <linux/blkdev.h>
30 #include <linux/backing-dev.h>
31 #include <linux/freezer.h>
32 #include <linux/kthread.h>
33 #include <linux/crc32.h>
34 #include <linux/pagevec.h>
35 #include <linux/slab.h>
36 #include "nilfs.h"
37 #include "btnode.h"
38 #include "page.h"
39 #include "segment.h"
40 #include "sufile.h"
41 #include "cpfile.h"
42 #include "ifile.h"
43 #include "segbuf.h"
44
45
46 /*
47 * Segment constructor
48 */
49 #define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */
50
51 #define SC_MAX_SEGDELTA 64 /* Upper limit of the number of segments
52 appended in collection retry loop */
53
54 /* Construction mode */
55 enum {
56 SC_LSEG_SR = 1, /* Make a logical segment having a super root */
57 SC_LSEG_DSYNC, /* Flush data blocks of a given file and make
58 a logical segment without a super root */
59 SC_FLUSH_FILE, /* Flush data files, leads to segment writes without
60 creating a checkpoint */
61 SC_FLUSH_DAT, /* Flush DAT file. This also creates segments without
62 a checkpoint */
63 };
64
65 /* Stage numbers of dirty block collection */
66 enum {
67 NILFS_ST_INIT = 0,
68 NILFS_ST_GC, /* Collecting dirty blocks for GC */
69 NILFS_ST_FILE,
70 NILFS_ST_IFILE,
71 NILFS_ST_CPFILE,
72 NILFS_ST_SUFILE,
73 NILFS_ST_DAT,
74 NILFS_ST_SR, /* Super root */
75 NILFS_ST_DSYNC, /* Data sync blocks */
76 NILFS_ST_DONE,
77 };
78
79 /* State flags of collection */
80 #define NILFS_CF_NODE 0x0001 /* Collecting node blocks */
81 #define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */
82 #define NILFS_CF_SUFREED 0x0004 /* segment usages has been freed */
83 #define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
84
85 /* Operations depending on the construction mode and file type */
86 struct nilfs_sc_operations {
87 int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *,
88 struct inode *);
89 int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *,
90 struct inode *);
91 int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *,
92 struct inode *);
93 void (*write_data_binfo)(struct nilfs_sc_info *,
94 struct nilfs_segsum_pointer *,
95 union nilfs_binfo *);
96 void (*write_node_binfo)(struct nilfs_sc_info *,
97 struct nilfs_segsum_pointer *,
98 union nilfs_binfo *);
99 };
100
101 /*
102 * Other definitions
103 */
104 static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
105 static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
106 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
107 static void nilfs_dispose_list(struct nilfs_sb_info *, struct list_head *,
108 int);
109
110 #define nilfs_cnt32_gt(a, b) \
111 (typecheck(__u32, a) && typecheck(__u32, b) && \
112 ((__s32)(b) - (__s32)(a) < 0))
113 #define nilfs_cnt32_ge(a, b) \
114 (typecheck(__u32, a) && typecheck(__u32, b) && \
115 ((__s32)(a) - (__s32)(b) >= 0))
116 #define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
117 #define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)
118
119 static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
120 {
121 struct nilfs_transaction_info *cur_ti = current->journal_info;
122 void *save = NULL;
123
124 if (cur_ti) {
125 if (cur_ti->ti_magic == NILFS_TI_MAGIC)
126 return ++cur_ti->ti_count;
127 else {
128 /*
129 * If journal_info field is occupied by other FS,
130 * it is saved and will be restored on
131 * nilfs_transaction_commit().
132 */
133 printk(KERN_WARNING
134 "NILFS warning: journal info from a different "
135 "FS\n");
136 save = current->journal_info;
137 }
138 }
139 if (!ti) {
140 ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
141 if (!ti)
142 return -ENOMEM;
143 ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
144 } else {
145 ti->ti_flags = 0;
146 }
147 ti->ti_count = 0;
148 ti->ti_save = save;
149 ti->ti_magic = NILFS_TI_MAGIC;
150 current->journal_info = ti;
151 return 0;
152 }
153
154 /**
155 * nilfs_transaction_begin - start indivisible file operations.
156 * @sb: super block
157 * @ti: nilfs_transaction_info
158 * @vacancy_check: flags for vacancy rate checks
159 *
160 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
161 * the segment semaphore, to make a segment construction and write tasks
162 * exclusive. The function is used with nilfs_transaction_commit() in pairs.
163 * The region enclosed by these two functions can be nested. To avoid a
164 * deadlock, the semaphore is only acquired or released in the outermost call.
165 *
166 * This function allocates a nilfs_transaction_info struct to keep context
167 * information on it. It is initialized and hooked onto the current task in
168 * the outermost call. If a pre-allocated struct is given to @ti, it is used
169 * instead; otherwise a new struct is assigned from a slab.
170 *
171 * When @vacancy_check flag is set, this function will check the amount of
172 * free space, and will wait for the GC to reclaim disk space if low capacity.
173 *
174 * Return Value: On success, 0 is returned. On error, one of the following
175 * negative error code is returned.
176 *
177 * %-ENOMEM - Insufficient memory available.
178 *
179 * %-ENOSPC - No space left on device
180 */
181 int nilfs_transaction_begin(struct super_block *sb,
182 struct nilfs_transaction_info *ti,
183 int vacancy_check)
184 {
185 struct nilfs_sb_info *sbi;
186 struct the_nilfs *nilfs;
187 int ret = nilfs_prepare_segment_lock(ti);
188
189 if (unlikely(ret < 0))
190 return ret;
191 if (ret > 0)
192 return 0;
193
194 vfs_check_frozen(sb, SB_FREEZE_WRITE);
195
196 sbi = NILFS_SB(sb);
197 nilfs = sbi->s_nilfs;
198 down_read(&nilfs->ns_segctor_sem);
199 if (vacancy_check && nilfs_near_disk_full(nilfs)) {
200 up_read(&nilfs->ns_segctor_sem);
201 ret = -ENOSPC;
202 goto failed;
203 }
204 return 0;
205
206 failed:
207 ti = current->journal_info;
208 current->journal_info = ti->ti_save;
209 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
210 kmem_cache_free(nilfs_transaction_cachep, ti);
211 return ret;
212 }
213
214 /**
215 * nilfs_transaction_commit - commit indivisible file operations.
216 * @sb: super block
217 *
218 * nilfs_transaction_commit() releases the read semaphore which is
219 * acquired by nilfs_transaction_begin(). This is only performed
220 * in outermost call of this function. If a commit flag is set,
221 * nilfs_transaction_commit() sets a timer to start the segment
222 * constructor. If a sync flag is set, it starts construction
223 * directly.
224 */
225 int nilfs_transaction_commit(struct super_block *sb)
226 {
227 struct nilfs_transaction_info *ti = current->journal_info;
228 struct nilfs_sb_info *sbi;
229 struct nilfs_sc_info *sci;
230 int err = 0;
231
232 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
233 ti->ti_flags |= NILFS_TI_COMMIT;
234 if (ti->ti_count > 0) {
235 ti->ti_count--;
236 return 0;
237 }
238 sbi = NILFS_SB(sb);
239 sci = NILFS_SC(sbi);
240 if (sci != NULL) {
241 if (ti->ti_flags & NILFS_TI_COMMIT)
242 nilfs_segctor_start_timer(sci);
243 if (atomic_read(&sbi->s_nilfs->ns_ndirtyblks) >
244 sci->sc_watermark)
245 nilfs_segctor_do_flush(sci, 0);
246 }
247 up_read(&sbi->s_nilfs->ns_segctor_sem);
248 current->journal_info = ti->ti_save;
249
250 if (ti->ti_flags & NILFS_TI_SYNC)
251 err = nilfs_construct_segment(sb);
252 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
253 kmem_cache_free(nilfs_transaction_cachep, ti);
254 return err;
255 }
256
257 void nilfs_transaction_abort(struct super_block *sb)
258 {
259 struct nilfs_transaction_info *ti = current->journal_info;
260
261 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
262 if (ti->ti_count > 0) {
263 ti->ti_count--;
264 return;
265 }
266 up_read(&NILFS_SB(sb)->s_nilfs->ns_segctor_sem);
267
268 current->journal_info = ti->ti_save;
269 if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
270 kmem_cache_free(nilfs_transaction_cachep, ti);
271 }
272
273 void nilfs_relax_pressure_in_lock(struct super_block *sb)
274 {
275 struct nilfs_sb_info *sbi = NILFS_SB(sb);
276 struct nilfs_sc_info *sci = NILFS_SC(sbi);
277 struct the_nilfs *nilfs = sbi->s_nilfs;
278
279 if (!sci || !sci->sc_flush_request)
280 return;
281
282 set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
283 up_read(&nilfs->ns_segctor_sem);
284
285 down_write(&nilfs->ns_segctor_sem);
286 if (sci->sc_flush_request &&
287 test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
288 struct nilfs_transaction_info *ti = current->journal_info;
289
290 ti->ti_flags |= NILFS_TI_WRITER;
291 nilfs_segctor_do_immediate_flush(sci);
292 ti->ti_flags &= ~NILFS_TI_WRITER;
293 }
294 downgrade_write(&nilfs->ns_segctor_sem);
295 }
296
297 static void nilfs_transaction_lock(struct nilfs_sb_info *sbi,
298 struct nilfs_transaction_info *ti,
299 int gcflag)
300 {
301 struct nilfs_transaction_info *cur_ti = current->journal_info;
302
303 WARN_ON(cur_ti);
304 ti->ti_flags = NILFS_TI_WRITER;
305 ti->ti_count = 0;
306 ti->ti_save = cur_ti;
307 ti->ti_magic = NILFS_TI_MAGIC;
308 INIT_LIST_HEAD(&ti->ti_garbage);
309 current->journal_info = ti;
310
311 for (;;) {
312 down_write(&sbi->s_nilfs->ns_segctor_sem);
313 if (!test_bit(NILFS_SC_PRIOR_FLUSH, &NILFS_SC(sbi)->sc_flags))
314 break;
315
316 nilfs_segctor_do_immediate_flush(NILFS_SC(sbi));
317
318 up_write(&sbi->s_nilfs->ns_segctor_sem);
319 yield();
320 }
321 if (gcflag)
322 ti->ti_flags |= NILFS_TI_GC;
323 }
324
325 static void nilfs_transaction_unlock(struct nilfs_sb_info *sbi)
326 {
327 struct nilfs_transaction_info *ti = current->journal_info;
328
329 BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
330 BUG_ON(ti->ti_count > 0);
331
332 up_write(&sbi->s_nilfs->ns_segctor_sem);
333 current->journal_info = ti->ti_save;
334 if (!list_empty(&ti->ti_garbage))
335 nilfs_dispose_list(sbi, &ti->ti_garbage, 0);
336 }
337
338 static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
339 struct nilfs_segsum_pointer *ssp,
340 unsigned bytes)
341 {
342 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
343 unsigned blocksize = sci->sc_super->s_blocksize;
344 void *p;
345
346 if (unlikely(ssp->offset + bytes > blocksize)) {
347 ssp->offset = 0;
348 BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
349 &segbuf->sb_segsum_buffers));
350 ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
351 }
352 p = ssp->bh->b_data + ssp->offset;
353 ssp->offset += bytes;
354 return p;
355 }
356
357 /**
358 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
359 * @sci: nilfs_sc_info
360 */
361 static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
362 {
363 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
364 struct buffer_head *sumbh;
365 unsigned sumbytes;
366 unsigned flags = 0;
367 int err;
368
369 if (nilfs_doing_gc())
370 flags = NILFS_SS_GC;
371 err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno);
372 if (unlikely(err))
373 return err;
374
375 sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
376 sumbytes = segbuf->sb_sum.sumbytes;
377 sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes;
378 sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes;
379 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
380 return 0;
381 }
382
383 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
384 {
385 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
386 if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
387 return -E2BIG; /* The current segment is filled up
388 (internal code) */
389 sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
390 return nilfs_segctor_reset_segment_buffer(sci);
391 }
392
393 static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
394 {
395 struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
396 int err;
397
398 if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
399 err = nilfs_segctor_feed_segment(sci);
400 if (err)
401 return err;
402 segbuf = sci->sc_curseg;
403 }
404 err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
405 if (likely(!err))
406 segbuf->sb_sum.flags |= NILFS_SS_SR;
407 return err;
408 }
409
410 /*
411 * Functions for making segment summary and payloads
412 */
413 static int nilfs_segctor_segsum_block_required(
414 struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
415 unsigned binfo_size)
416 {
417 unsigned blocksize = sci->sc_super->s_blocksize;
418 /* Size of finfo and binfo is enough small against blocksize */
419
420 return ssp->offset + binfo_size +
421 (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
422 blocksize;
423 }
424
425 static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
426 struct inode *inode)
427 {
428 sci->sc_curseg->sb_sum.nfinfo++;
429 sci->sc_binfo_ptr = sci->sc_finfo_ptr;
430 nilfs_segctor_map_segsum_entry(
431 sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
432
433 if (inode->i_sb && !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
434 set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
435 /* skip finfo */
436 }
437
438 static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
439 struct inode *inode)
440 {
441 struct nilfs_finfo *finfo;
442 struct nilfs_inode_info *ii;
443 struct nilfs_segment_buffer *segbuf;
444 __u64 cno;
445
446 if (sci->sc_blk_cnt == 0)
447 return;
448
449 ii = NILFS_I(inode);
450
451 if (test_bit(NILFS_I_GCINODE, &ii->i_state))
452 cno = ii->i_cno;
453 else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
454 cno = 0;
455 else
456 cno = sci->sc_cno;
457
458 finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
459 sizeof(*finfo));
460 finfo->fi_ino = cpu_to_le64(inode->i_ino);
461 finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
462 finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
463 finfo->fi_cno = cpu_to_le64(cno);
464
465 segbuf = sci->sc_curseg;
466 segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
467 sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
468 sci->sc_finfo_ptr = sci->sc_binfo_ptr;
469 sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
470 }
471
472 static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
473 struct buffer_head *bh,
474 struct inode *inode,
475 unsigned binfo_size)
476 {
477 struct nilfs_segment_buffer *segbuf;
478 int required, err = 0;
479
480 retry:
481 segbuf = sci->sc_curseg;
482 required = nilfs_segctor_segsum_block_required(
483 sci, &sci->sc_binfo_ptr, binfo_size);
484 if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
485 nilfs_segctor_end_finfo(sci, inode);
486 err = nilfs_segctor_feed_segment(sci);
487 if (err)
488 return err;
489 goto retry;
490 }
491 if (unlikely(required)) {
492 err = nilfs_segbuf_extend_segsum(segbuf);
493 if (unlikely(err))
494 goto failed;
495 }
496 if (sci->sc_blk_cnt == 0)
497 nilfs_segctor_begin_finfo(sci, inode);
498
499 nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
500 /* Substitution to vblocknr is delayed until update_blocknr() */
501 nilfs_segbuf_add_file_buffer(segbuf, bh);
502 sci->sc_blk_cnt++;
503 failed:
504 return err;
505 }
506
507 static int nilfs_handle_bmap_error(int err, const char *fname,
508 struct inode *inode, struct super_block *sb)
509 {
510 if (err == -EINVAL) {
511 nilfs_error(sb, fname, "broken bmap (inode=%lu)\n",
512 inode->i_ino);
513 err = -EIO;
514 }
515 return err;
516 }
517
518 /*
519 * Callback functions that enumerate, mark, and collect dirty blocks
520 */
521 static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
522 struct buffer_head *bh, struct inode *inode)
523 {
524 int err;
525
526 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
527 if (unlikely(err < 0))
528 return nilfs_handle_bmap_error(err, __func__, inode,
529 sci->sc_super);
530
531 err = nilfs_segctor_add_file_block(sci, bh, inode,
532 sizeof(struct nilfs_binfo_v));
533 if (!err)
534 sci->sc_datablk_cnt++;
535 return err;
536 }
537
538 static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
539 struct buffer_head *bh,
540 struct inode *inode)
541 {
542 int err;
543
544 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
545 if (unlikely(err < 0))
546 return nilfs_handle_bmap_error(err, __func__, inode,
547 sci->sc_super);
548 return 0;
549 }
550
551 static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
552 struct buffer_head *bh,
553 struct inode *inode)
554 {
555 WARN_ON(!buffer_dirty(bh));
556 return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
557 }
558
559 static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
560 struct nilfs_segsum_pointer *ssp,
561 union nilfs_binfo *binfo)
562 {
563 struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
564 sci, ssp, sizeof(*binfo_v));
565 *binfo_v = binfo->bi_v;
566 }
567
568 static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
569 struct nilfs_segsum_pointer *ssp,
570 union nilfs_binfo *binfo)
571 {
572 __le64 *vblocknr = nilfs_segctor_map_segsum_entry(
573 sci, ssp, sizeof(*vblocknr));
574 *vblocknr = binfo->bi_v.bi_vblocknr;
575 }
576
577 static struct nilfs_sc_operations nilfs_sc_file_ops = {
578 .collect_data = nilfs_collect_file_data,
579 .collect_node = nilfs_collect_file_node,
580 .collect_bmap = nilfs_collect_file_bmap,
581 .write_data_binfo = nilfs_write_file_data_binfo,
582 .write_node_binfo = nilfs_write_file_node_binfo,
583 };
584
585 static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
586 struct buffer_head *bh, struct inode *inode)
587 {
588 int err;
589
590 err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
591 if (unlikely(err < 0))
592 return nilfs_handle_bmap_error(err, __func__, inode,
593 sci->sc_super);
594
595 err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
596 if (!err)
597 sci->sc_datablk_cnt++;
598 return err;
599 }
600
601 static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
602 struct buffer_head *bh, struct inode *inode)
603 {
604 WARN_ON(!buffer_dirty(bh));
605 return nilfs_segctor_add_file_block(sci, bh, inode,
606 sizeof(struct nilfs_binfo_dat));
607 }
608
609 static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
610 struct nilfs_segsum_pointer *ssp,
611 union nilfs_binfo *binfo)
612 {
613 __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
614 sizeof(*blkoff));
615 *blkoff = binfo->bi_dat.bi_blkoff;
616 }
617
618 static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
619 struct nilfs_segsum_pointer *ssp,
620 union nilfs_binfo *binfo)
621 {
622 struct nilfs_binfo_dat *binfo_dat =
623 nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
624 *binfo_dat = binfo->bi_dat;
625 }
626
627 static struct nilfs_sc_operations nilfs_sc_dat_ops = {
628 .collect_data = nilfs_collect_dat_data,
629 .collect_node = nilfs_collect_file_node,
630 .collect_bmap = nilfs_collect_dat_bmap,
631 .write_data_binfo = nilfs_write_dat_data_binfo,
632 .write_node_binfo = nilfs_write_dat_node_binfo,
633 };
634
635 static struct nilfs_sc_operations nilfs_sc_dsync_ops = {
636 .collect_data = nilfs_collect_file_data,
637 .collect_node = NULL,
638 .collect_bmap = NULL,
639 .write_data_binfo = nilfs_write_file_data_binfo,
640 .write_node_binfo = NULL,
641 };
642
643 static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
644 struct list_head *listp,
645 size_t nlimit,
646 loff_t start, loff_t end)
647 {
648 struct address_space *mapping = inode->i_mapping;
649 struct pagevec pvec;
650 pgoff_t index = 0, last = ULONG_MAX;
651 size_t ndirties = 0;
652 int i;
653
654 if (unlikely(start != 0 || end != LLONG_MAX)) {
655 /*
656 * A valid range is given for sync-ing data pages. The
657 * range is rounded to per-page; extra dirty buffers
658 * may be included if blocksize < pagesize.
659 */
660 index = start >> PAGE_SHIFT;
661 last = end >> PAGE_SHIFT;
662 }
663 pagevec_init(&pvec, 0);
664 repeat:
665 if (unlikely(index > last) ||
666 !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
667 min_t(pgoff_t, last - index,
668 PAGEVEC_SIZE - 1) + 1))
669 return ndirties;
670
671 for (i = 0; i < pagevec_count(&pvec); i++) {
672 struct buffer_head *bh, *head;
673 struct page *page = pvec.pages[i];
674
675 if (unlikely(page->index > last))
676 break;
677
678 if (mapping->host) {
679 lock_page(page);
680 if (!page_has_buffers(page))
681 create_empty_buffers(page,
682 1 << inode->i_blkbits, 0);
683 unlock_page(page);
684 }
685
686 bh = head = page_buffers(page);
687 do {
688 if (!buffer_dirty(bh))
689 continue;
690 get_bh(bh);
691 list_add_tail(&bh->b_assoc_buffers, listp);
692 ndirties++;
693 if (unlikely(ndirties >= nlimit)) {
694 pagevec_release(&pvec);
695 cond_resched();
696 return ndirties;
697 }
698 } while (bh = bh->b_this_page, bh != head);
699 }
700 pagevec_release(&pvec);
701 cond_resched();
702 goto repeat;
703 }
704
705 static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
706 struct list_head *listp)
707 {
708 struct nilfs_inode_info *ii = NILFS_I(inode);
709 struct address_space *mapping = &ii->i_btnode_cache;
710 struct pagevec pvec;
711 struct buffer_head *bh, *head;
712 unsigned int i;
713 pgoff_t index = 0;
714
715 pagevec_init(&pvec, 0);
716
717 while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
718 PAGEVEC_SIZE)) {
719 for (i = 0; i < pagevec_count(&pvec); i++) {
720 bh = head = page_buffers(pvec.pages[i]);
721 do {
722 if (buffer_dirty(bh)) {
723 get_bh(bh);
724 list_add_tail(&bh->b_assoc_buffers,
725 listp);
726 }
727 bh = bh->b_this_page;
728 } while (bh != head);
729 }
730 pagevec_release(&pvec);
731 cond_resched();
732 }
733 }
734
735 static void nilfs_dispose_list(struct nilfs_sb_info *sbi,
736 struct list_head *head, int force)
737 {
738 struct nilfs_inode_info *ii, *n;
739 struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
740 unsigned nv = 0;
741
742 while (!list_empty(head)) {
743 spin_lock(&sbi->s_inode_lock);
744 list_for_each_entry_safe(ii, n, head, i_dirty) {
745 list_del_init(&ii->i_dirty);
746 if (force) {
747 if (unlikely(ii->i_bh)) {
748 brelse(ii->i_bh);
749 ii->i_bh = NULL;
750 }
751 } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
752 set_bit(NILFS_I_QUEUED, &ii->i_state);
753 list_add_tail(&ii->i_dirty,
754 &sbi->s_dirty_files);
755 continue;
756 }
757 ivec[nv++] = ii;
758 if (nv == SC_N_INODEVEC)
759 break;
760 }
761 spin_unlock(&sbi->s_inode_lock);
762
763 for (pii = ivec; nv > 0; pii++, nv--)
764 iput(&(*pii)->vfs_inode);
765 }
766 }
767
768 static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
769 struct nilfs_root *root)
770 {
771 int ret = 0;
772
773 if (nilfs_mdt_fetch_dirty(root->ifile))
774 ret++;
775 if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
776 ret++;
777 if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
778 ret++;
779 if (ret || nilfs_doing_gc())
780 if (nilfs_mdt_fetch_dirty(nilfs_dat_inode(nilfs)))
781 ret++;
782 return ret;
783 }
784
785 static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
786 {
787 return list_empty(&sci->sc_dirty_files) &&
788 !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
789 sci->sc_nfreesegs == 0 &&
790 (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
791 }
792
793 static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
794 {
795 struct nilfs_sb_info *sbi = sci->sc_sbi;
796 int ret = 0;
797
798 if (nilfs_test_metadata_dirty(sbi->s_nilfs, sci->sc_root))
799 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
800
801 spin_lock(&sbi->s_inode_lock);
802 if (list_empty(&sbi->s_dirty_files) && nilfs_segctor_clean(sci))
803 ret++;
804
805 spin_unlock(&sbi->s_inode_lock);
806 return ret;
807 }
808
809 static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
810 {
811 struct nilfs_sb_info *sbi = sci->sc_sbi;
812 struct the_nilfs *nilfs = sbi->s_nilfs;
813
814 nilfs_mdt_clear_dirty(sci->sc_root->ifile);
815 nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
816 nilfs_mdt_clear_dirty(nilfs->ns_sufile);
817 nilfs_mdt_clear_dirty(nilfs_dat_inode(nilfs));
818 }
819
820 static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
821 {
822 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
823 struct buffer_head *bh_cp;
824 struct nilfs_checkpoint *raw_cp;
825 int err;
826
827 /* XXX: this interface will be changed */
828 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
829 &raw_cp, &bh_cp);
830 if (likely(!err)) {
831 /* The following code is duplicated with cpfile. But, it is
832 needed to collect the checkpoint even if it was not newly
833 created */
834 nilfs_mdt_mark_buffer_dirty(bh_cp);
835 nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
836 nilfs_cpfile_put_checkpoint(
837 nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
838 } else
839 WARN_ON(err == -EINVAL || err == -ENOENT);
840
841 return err;
842 }
843
844 static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
845 {
846 struct nilfs_sb_info *sbi = sci->sc_sbi;
847 struct the_nilfs *nilfs = sbi->s_nilfs;
848 struct buffer_head *bh_cp;
849 struct nilfs_checkpoint *raw_cp;
850 int err;
851
852 err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
853 &raw_cp, &bh_cp);
854 if (unlikely(err)) {
855 WARN_ON(err == -EINVAL || err == -ENOENT);
856 goto failed_ibh;
857 }
858 raw_cp->cp_snapshot_list.ssl_next = 0;
859 raw_cp->cp_snapshot_list.ssl_prev = 0;
860 raw_cp->cp_inodes_count =
861 cpu_to_le64(atomic_read(&sci->sc_root->inodes_count));
862 raw_cp->cp_blocks_count =
863 cpu_to_le64(atomic_read(&sci->sc_root->blocks_count));
864 raw_cp->cp_nblk_inc =
865 cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
866 raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
867 raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
868
869 if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
870 nilfs_checkpoint_clear_minor(raw_cp);
871 else
872 nilfs_checkpoint_set_minor(raw_cp);
873
874 nilfs_write_inode_common(sci->sc_root->ifile,
875 &raw_cp->cp_ifile_inode, 1);
876 nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
877 return 0;
878
879 failed_ibh:
880 return err;
881 }
882
883 static void nilfs_fill_in_file_bmap(struct inode *ifile,
884 struct nilfs_inode_info *ii)
885
886 {
887 struct buffer_head *ibh;
888 struct nilfs_inode *raw_inode;
889
890 if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
891 ibh = ii->i_bh;
892 BUG_ON(!ibh);
893 raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
894 ibh);
895 nilfs_bmap_write(ii->i_bmap, raw_inode);
896 nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
897 }
898 }
899
900 static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
901 {
902 struct nilfs_inode_info *ii;
903
904 list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
905 nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
906 set_bit(NILFS_I_COLLECTED, &ii->i_state);
907 }
908 }
909
910 static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
911 struct the_nilfs *nilfs)
912 {
913 struct buffer_head *bh_sr;
914 struct nilfs_super_root *raw_sr;
915 unsigned isz = nilfs->ns_inode_size;
916
917 bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
918 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
919
920 raw_sr->sr_bytes = cpu_to_le16(NILFS_SR_BYTES);
921 raw_sr->sr_nongc_ctime
922 = cpu_to_le64(nilfs_doing_gc() ?
923 nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
924 raw_sr->sr_flags = 0;
925
926 nilfs_write_inode_common(nilfs_dat_inode(nilfs), (void *)raw_sr +
927 NILFS_SR_DAT_OFFSET(isz), 1);
928 nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
929 NILFS_SR_CPFILE_OFFSET(isz), 1);
930 nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
931 NILFS_SR_SUFILE_OFFSET(isz), 1);
932 }
933
934 static void nilfs_redirty_inodes(struct list_head *head)
935 {
936 struct nilfs_inode_info *ii;
937
938 list_for_each_entry(ii, head, i_dirty) {
939 if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
940 clear_bit(NILFS_I_COLLECTED, &ii->i_state);
941 }
942 }
943
944 static void nilfs_drop_collected_inodes(struct list_head *head)
945 {
946 struct nilfs_inode_info *ii;
947
948 list_for_each_entry(ii, head, i_dirty) {
949 if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
950 continue;
951
952 clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
953 set_bit(NILFS_I_UPDATED, &ii->i_state);
954 }
955 }
956
957 static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
958 struct inode *inode,
959 struct list_head *listp,
960 int (*collect)(struct nilfs_sc_info *,
961 struct buffer_head *,
962 struct inode *))
963 {
964 struct buffer_head *bh, *n;
965 int err = 0;
966
967 if (collect) {
968 list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
969 list_del_init(&bh->b_assoc_buffers);
970 err = collect(sci, bh, inode);
971 brelse(bh);
972 if (unlikely(err))
973 goto dispose_buffers;
974 }
975 return 0;
976 }
977
978 dispose_buffers:
979 while (!list_empty(listp)) {
980 bh = list_entry(listp->next, struct buffer_head,
981 b_assoc_buffers);
982 list_del_init(&bh->b_assoc_buffers);
983 brelse(bh);
984 }
985 return err;
986 }
987
988 static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
989 {
990 /* Remaining number of blocks within segment buffer */
991 return sci->sc_segbuf_nblocks -
992 (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
993 }
994
995 static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
996 struct inode *inode,
997 struct nilfs_sc_operations *sc_ops)
998 {
999 LIST_HEAD(data_buffers);
1000 LIST_HEAD(node_buffers);
1001 int err;
1002
1003 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1004 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1005
1006 n = nilfs_lookup_dirty_data_buffers(
1007 inode, &data_buffers, rest + 1, 0, LLONG_MAX);
1008 if (n > rest) {
1009 err = nilfs_segctor_apply_buffers(
1010 sci, inode, &data_buffers,
1011 sc_ops->collect_data);
1012 BUG_ON(!err); /* always receive -E2BIG or true error */
1013 goto break_or_fail;
1014 }
1015 }
1016 nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1017
1018 if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1019 err = nilfs_segctor_apply_buffers(
1020 sci, inode, &data_buffers, sc_ops->collect_data);
1021 if (unlikely(err)) {
1022 /* dispose node list */
1023 nilfs_segctor_apply_buffers(
1024 sci, inode, &node_buffers, NULL);
1025 goto break_or_fail;
1026 }
1027 sci->sc_stage.flags |= NILFS_CF_NODE;
1028 }
1029 /* Collect node */
1030 err = nilfs_segctor_apply_buffers(
1031 sci, inode, &node_buffers, sc_ops->collect_node);
1032 if (unlikely(err))
1033 goto break_or_fail;
1034
1035 nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1036 err = nilfs_segctor_apply_buffers(
1037 sci, inode, &node_buffers, sc_ops->collect_bmap);
1038 if (unlikely(err))
1039 goto break_or_fail;
1040
1041 nilfs_segctor_end_finfo(sci, inode);
1042 sci->sc_stage.flags &= ~NILFS_CF_NODE;
1043
1044 break_or_fail:
1045 return err;
1046 }
1047
1048 static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1049 struct inode *inode)
1050 {
1051 LIST_HEAD(data_buffers);
1052 size_t n, rest = nilfs_segctor_buffer_rest(sci);
1053 int err;
1054
1055 n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1056 sci->sc_dsync_start,
1057 sci->sc_dsync_end);
1058
1059 err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1060 nilfs_collect_file_data);
1061 if (!err) {
1062 nilfs_segctor_end_finfo(sci, inode);
1063 BUG_ON(n > rest);
1064 /* always receive -E2BIG or true error if n > rest */
1065 }
1066 return err;
1067 }
1068
1069 static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1070 {
1071 struct nilfs_sb_info *sbi = sci->sc_sbi;
1072 struct the_nilfs *nilfs = sbi->s_nilfs;
1073 struct list_head *head;
1074 struct nilfs_inode_info *ii;
1075 size_t ndone;
1076 int err = 0;
1077
1078 switch (sci->sc_stage.scnt) {
1079 case NILFS_ST_INIT:
1080 /* Pre-processes */
1081 sci->sc_stage.flags = 0;
1082
1083 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1084 sci->sc_nblk_inc = 0;
1085 sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1086 if (mode == SC_LSEG_DSYNC) {
1087 sci->sc_stage.scnt = NILFS_ST_DSYNC;
1088 goto dsync_mode;
1089 }
1090 }
1091
1092 sci->sc_stage.dirty_file_ptr = NULL;
1093 sci->sc_stage.gc_inode_ptr = NULL;
1094 if (mode == SC_FLUSH_DAT) {
1095 sci->sc_stage.scnt = NILFS_ST_DAT;
1096 goto dat_stage;
1097 }
1098 sci->sc_stage.scnt++; /* Fall through */
1099 case NILFS_ST_GC:
1100 if (nilfs_doing_gc()) {
1101 head = &sci->sc_gc_inodes;
1102 ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1103 head, i_dirty);
1104 list_for_each_entry_continue(ii, head, i_dirty) {
1105 err = nilfs_segctor_scan_file(
1106 sci, &ii->vfs_inode,
1107 &nilfs_sc_file_ops);
1108 if (unlikely(err)) {
1109 sci->sc_stage.gc_inode_ptr = list_entry(
1110 ii->i_dirty.prev,
1111 struct nilfs_inode_info,
1112 i_dirty);
1113 goto break_or_fail;
1114 }
1115 set_bit(NILFS_I_COLLECTED, &ii->i_state);
1116 }
1117 sci->sc_stage.gc_inode_ptr = NULL;
1118 }
1119 sci->sc_stage.scnt++; /* Fall through */
1120 case NILFS_ST_FILE:
1121 head = &sci->sc_dirty_files;
1122 ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1123 i_dirty);
1124 list_for_each_entry_continue(ii, head, i_dirty) {
1125 clear_bit(NILFS_I_DIRTY, &ii->i_state);
1126
1127 err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1128 &nilfs_sc_file_ops);
1129 if (unlikely(err)) {
1130 sci->sc_stage.dirty_file_ptr =
1131 list_entry(ii->i_dirty.prev,
1132 struct nilfs_inode_info,
1133 i_dirty);
1134 goto break_or_fail;
1135 }
1136 /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1137 /* XXX: required ? */
1138 }
1139 sci->sc_stage.dirty_file_ptr = NULL;
1140 if (mode == SC_FLUSH_FILE) {
1141 sci->sc_stage.scnt = NILFS_ST_DONE;
1142 return 0;
1143 }
1144 sci->sc_stage.scnt++;
1145 sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1146 /* Fall through */
1147 case NILFS_ST_IFILE:
1148 err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1149 &nilfs_sc_file_ops);
1150 if (unlikely(err))
1151 break;
1152 sci->sc_stage.scnt++;
1153 /* Creating a checkpoint */
1154 err = nilfs_segctor_create_checkpoint(sci);
1155 if (unlikely(err))
1156 break;
1157 /* Fall through */
1158 case NILFS_ST_CPFILE:
1159 err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1160 &nilfs_sc_file_ops);
1161 if (unlikely(err))
1162 break;
1163 sci->sc_stage.scnt++; /* Fall through */
1164 case NILFS_ST_SUFILE:
1165 err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1166 sci->sc_nfreesegs, &ndone);
1167 if (unlikely(err)) {
1168 nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1169 sci->sc_freesegs, ndone,
1170 NULL);
1171 break;
1172 }
1173 sci->sc_stage.flags |= NILFS_CF_SUFREED;
1174
1175 err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1176 &nilfs_sc_file_ops);
1177 if (unlikely(err))
1178 break;
1179 sci->sc_stage.scnt++; /* Fall through */
1180 case NILFS_ST_DAT:
1181 dat_stage:
1182 err = nilfs_segctor_scan_file(sci, nilfs_dat_inode(nilfs),
1183 &nilfs_sc_dat_ops);
1184 if (unlikely(err))
1185 break;
1186 if (mode == SC_FLUSH_DAT) {
1187 sci->sc_stage.scnt = NILFS_ST_DONE;
1188 return 0;
1189 }
1190 sci->sc_stage.scnt++; /* Fall through */
1191 case NILFS_ST_SR:
1192 if (mode == SC_LSEG_SR) {
1193 /* Appending a super root */
1194 err = nilfs_segctor_add_super_root(sci);
1195 if (unlikely(err))
1196 break;
1197 }
1198 /* End of a logical segment */
1199 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1200 sci->sc_stage.scnt = NILFS_ST_DONE;
1201 return 0;
1202 case NILFS_ST_DSYNC:
1203 dsync_mode:
1204 sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1205 ii = sci->sc_dsync_inode;
1206 if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1207 break;
1208
1209 err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1210 if (unlikely(err))
1211 break;
1212 sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1213 sci->sc_stage.scnt = NILFS_ST_DONE;
1214 return 0;
1215 case NILFS_ST_DONE:
1216 return 0;
1217 default:
1218 BUG();
1219 }
1220
1221 break_or_fail:
1222 return err;
1223 }
1224
1225 /**
1226 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1227 * @sci: nilfs_sc_info
1228 * @nilfs: nilfs object
1229 */
1230 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1231 struct the_nilfs *nilfs)
1232 {
1233 struct nilfs_segment_buffer *segbuf, *prev;
1234 __u64 nextnum;
1235 int err, alloc = 0;
1236
1237 segbuf = nilfs_segbuf_new(sci->sc_super);
1238 if (unlikely(!segbuf))
1239 return -ENOMEM;
1240
1241 if (list_empty(&sci->sc_write_logs)) {
1242 nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1243 nilfs->ns_pseg_offset, nilfs);
1244 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1245 nilfs_shift_to_next_segment(nilfs);
1246 nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1247 }
1248
1249 segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1250 nextnum = nilfs->ns_nextnum;
1251
1252 if (nilfs->ns_segnum == nilfs->ns_nextnum)
1253 /* Start from the head of a new full segment */
1254 alloc++;
1255 } else {
1256 /* Continue logs */
1257 prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1258 nilfs_segbuf_map_cont(segbuf, prev);
1259 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1260 nextnum = prev->sb_nextnum;
1261
1262 if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1263 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1264 segbuf->sb_sum.seg_seq++;
1265 alloc++;
1266 }
1267 }
1268
1269 err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1270 if (err)
1271 goto failed;
1272
1273 if (alloc) {
1274 err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1275 if (err)
1276 goto failed;
1277 }
1278 nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1279
1280 BUG_ON(!list_empty(&sci->sc_segbufs));
1281 list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1282 sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1283 return 0;
1284
1285 failed:
1286 nilfs_segbuf_free(segbuf);
1287 return err;
1288 }
1289
1290 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1291 struct the_nilfs *nilfs, int nadd)
1292 {
1293 struct nilfs_segment_buffer *segbuf, *prev;
1294 struct inode *sufile = nilfs->ns_sufile;
1295 __u64 nextnextnum;
1296 LIST_HEAD(list);
1297 int err, ret, i;
1298
1299 prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1300 /*
1301 * Since the segment specified with nextnum might be allocated during
1302 * the previous construction, the buffer including its segusage may
1303 * not be dirty. The following call ensures that the buffer is dirty
1304 * and will pin the buffer on memory until the sufile is written.
1305 */
1306 err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1307 if (unlikely(err))
1308 return err;
1309
1310 for (i = 0; i < nadd; i++) {
1311 /* extend segment info */
1312 err = -ENOMEM;
1313 segbuf = nilfs_segbuf_new(sci->sc_super);
1314 if (unlikely(!segbuf))
1315 goto failed;
1316
1317 /* map this buffer to region of segment on-disk */
1318 nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1319 sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1320
1321 /* allocate the next next full segment */
1322 err = nilfs_sufile_alloc(sufile, &nextnextnum);
1323 if (unlikely(err))
1324 goto failed_segbuf;
1325
1326 segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1327 nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1328
1329 list_add_tail(&segbuf->sb_list, &list);
1330 prev = segbuf;
1331 }
1332 list_splice_tail(&list, &sci->sc_segbufs);
1333 return 0;
1334
1335 failed_segbuf:
1336 nilfs_segbuf_free(segbuf);
1337 failed:
1338 list_for_each_entry(segbuf, &list, sb_list) {
1339 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1340 WARN_ON(ret); /* never fails */
1341 }
1342 nilfs_destroy_logs(&list);
1343 return err;
1344 }
1345
1346 static void nilfs_free_incomplete_logs(struct list_head *logs,
1347 struct the_nilfs *nilfs)
1348 {
1349 struct nilfs_segment_buffer *segbuf, *prev;
1350 struct inode *sufile = nilfs->ns_sufile;
1351 int ret;
1352
1353 segbuf = NILFS_FIRST_SEGBUF(logs);
1354 if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1355 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1356 WARN_ON(ret); /* never fails */
1357 }
1358 if (atomic_read(&segbuf->sb_err)) {
1359 /* Case 1: The first segment failed */
1360 if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1361 /* Case 1a: Partial segment appended into an existing
1362 segment */
1363 nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1364 segbuf->sb_fseg_end);
1365 else /* Case 1b: New full segment */
1366 set_nilfs_discontinued(nilfs);
1367 }
1368
1369 prev = segbuf;
1370 list_for_each_entry_continue(segbuf, logs, sb_list) {
1371 if (prev->sb_nextnum != segbuf->sb_nextnum) {
1372 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1373 WARN_ON(ret); /* never fails */
1374 }
1375 if (atomic_read(&segbuf->sb_err) &&
1376 segbuf->sb_segnum != nilfs->ns_nextnum)
1377 /* Case 2: extended segment (!= next) failed */
1378 nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1379 prev = segbuf;
1380 }
1381 }
1382
1383 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1384 struct inode *sufile)
1385 {
1386 struct nilfs_segment_buffer *segbuf;
1387 unsigned long live_blocks;
1388 int ret;
1389
1390 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1391 live_blocks = segbuf->sb_sum.nblocks +
1392 (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1393 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1394 live_blocks,
1395 sci->sc_seg_ctime);
1396 WARN_ON(ret); /* always succeed because the segusage is dirty */
1397 }
1398 }
1399
1400 static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1401 {
1402 struct nilfs_segment_buffer *segbuf;
1403 int ret;
1404
1405 segbuf = NILFS_FIRST_SEGBUF(logs);
1406 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1407 segbuf->sb_pseg_start -
1408 segbuf->sb_fseg_start, 0);
1409 WARN_ON(ret); /* always succeed because the segusage is dirty */
1410
1411 list_for_each_entry_continue(segbuf, logs, sb_list) {
1412 ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1413 0, 0);
1414 WARN_ON(ret); /* always succeed */
1415 }
1416 }
1417
1418 static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1419 struct nilfs_segment_buffer *last,
1420 struct inode *sufile)
1421 {
1422 struct nilfs_segment_buffer *segbuf = last;
1423 int ret;
1424
1425 list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1426 sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1427 ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1428 WARN_ON(ret);
1429 }
1430 nilfs_truncate_logs(&sci->sc_segbufs, last);
1431 }
1432
1433
1434 static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1435 struct the_nilfs *nilfs, int mode)
1436 {
1437 struct nilfs_cstage prev_stage = sci->sc_stage;
1438 int err, nadd = 1;
1439
1440 /* Collection retry loop */
1441 for (;;) {
1442 sci->sc_nblk_this_inc = 0;
1443 sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1444
1445 err = nilfs_segctor_reset_segment_buffer(sci);
1446 if (unlikely(err))
1447 goto failed;
1448
1449 err = nilfs_segctor_collect_blocks(sci, mode);
1450 sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1451 if (!err)
1452 break;
1453
1454 if (unlikely(err != -E2BIG))
1455 goto failed;
1456
1457 /* The current segment is filled up */
1458 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
1459 break;
1460
1461 nilfs_clear_logs(&sci->sc_segbufs);
1462
1463 err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1464 if (unlikely(err))
1465 return err;
1466
1467 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1468 err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1469 sci->sc_freesegs,
1470 sci->sc_nfreesegs,
1471 NULL);
1472 WARN_ON(err); /* do not happen */
1473 }
1474 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1475 sci->sc_stage = prev_stage;
1476 }
1477 nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1478 return 0;
1479
1480 failed:
1481 return err;
1482 }
1483
1484 static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1485 struct buffer_head *new_bh)
1486 {
1487 BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1488
1489 list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1490 /* The caller must release old_bh */
1491 }
1492
1493 static int
1494 nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1495 struct nilfs_segment_buffer *segbuf,
1496 int mode)
1497 {
1498 struct inode *inode = NULL;
1499 sector_t blocknr;
1500 unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1501 unsigned long nblocks = 0, ndatablk = 0;
1502 struct nilfs_sc_operations *sc_op = NULL;
1503 struct nilfs_segsum_pointer ssp;
1504 struct nilfs_finfo *finfo = NULL;
1505 union nilfs_binfo binfo;
1506 struct buffer_head *bh, *bh_org;
1507 ino_t ino = 0;
1508 int err = 0;
1509
1510 if (!nfinfo)
1511 goto out;
1512
1513 blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1514 ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1515 ssp.offset = sizeof(struct nilfs_segment_summary);
1516
1517 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1518 if (bh == segbuf->sb_super_root)
1519 break;
1520 if (!finfo) {
1521 finfo = nilfs_segctor_map_segsum_entry(
1522 sci, &ssp, sizeof(*finfo));
1523 ino = le64_to_cpu(finfo->fi_ino);
1524 nblocks = le32_to_cpu(finfo->fi_nblocks);
1525 ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1526
1527 if (buffer_nilfs_node(bh))
1528 inode = NILFS_BTNC_I(bh->b_page->mapping);
1529 else
1530 inode = NILFS_AS_I(bh->b_page->mapping);
1531
1532 if (mode == SC_LSEG_DSYNC)
1533 sc_op = &nilfs_sc_dsync_ops;
1534 else if (ino == NILFS_DAT_INO)
1535 sc_op = &nilfs_sc_dat_ops;
1536 else /* file blocks */
1537 sc_op = &nilfs_sc_file_ops;
1538 }
1539 bh_org = bh;
1540 get_bh(bh_org);
1541 err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1542 &binfo);
1543 if (bh != bh_org)
1544 nilfs_list_replace_buffer(bh_org, bh);
1545 brelse(bh_org);
1546 if (unlikely(err))
1547 goto failed_bmap;
1548
1549 if (ndatablk > 0)
1550 sc_op->write_data_binfo(sci, &ssp, &binfo);
1551 else
1552 sc_op->write_node_binfo(sci, &ssp, &binfo);
1553
1554 blocknr++;
1555 if (--nblocks == 0) {
1556 finfo = NULL;
1557 if (--nfinfo == 0)
1558 break;
1559 } else if (ndatablk > 0)
1560 ndatablk--;
1561 }
1562 out:
1563 return 0;
1564
1565 failed_bmap:
1566 err = nilfs_handle_bmap_error(err, __func__, inode, sci->sc_super);
1567 return err;
1568 }
1569
1570 static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1571 {
1572 struct nilfs_segment_buffer *segbuf;
1573 int err;
1574
1575 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1576 err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1577 if (unlikely(err))
1578 return err;
1579 nilfs_segbuf_fill_in_segsum(segbuf);
1580 }
1581 return 0;
1582 }
1583
1584 static int
1585 nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out)
1586 {
1587 struct page *clone_page;
1588 struct buffer_head *bh, *head, *bh2;
1589 void *kaddr;
1590
1591 bh = head = page_buffers(page);
1592
1593 clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0);
1594 if (unlikely(!clone_page))
1595 return -ENOMEM;
1596
1597 bh2 = page_buffers(clone_page);
1598 kaddr = kmap_atomic(page, KM_USER0);
1599 do {
1600 if (list_empty(&bh->b_assoc_buffers))
1601 continue;
1602 get_bh(bh2);
1603 page_cache_get(clone_page); /* for each bh */
1604 memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size);
1605 bh2->b_blocknr = bh->b_blocknr;
1606 list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers);
1607 list_add_tail(&bh->b_assoc_buffers, out);
1608 } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head);
1609 kunmap_atomic(kaddr, KM_USER0);
1610
1611 if (!TestSetPageWriteback(clone_page))
1612 account_page_writeback(clone_page);
1613 unlock_page(clone_page);
1614
1615 return 0;
1616 }
1617
1618 static int nilfs_test_page_to_be_frozen(struct page *page)
1619 {
1620 struct address_space *mapping = page->mapping;
1621
1622 if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode))
1623 return 0;
1624
1625 if (page_mapped(page)) {
1626 ClearPageChecked(page);
1627 return 1;
1628 }
1629 return PageChecked(page);
1630 }
1631
1632 static int nilfs_begin_page_io(struct page *page, struct list_head *out)
1633 {
1634 if (!page || PageWriteback(page))
1635 /* For split b-tree node pages, this function may be called
1636 twice. We ignore the 2nd or later calls by this check. */
1637 return 0;
1638
1639 lock_page(page);
1640 clear_page_dirty_for_io(page);
1641 set_page_writeback(page);
1642 unlock_page(page);
1643
1644 if (nilfs_test_page_to_be_frozen(page)) {
1645 int err = nilfs_copy_replace_page_buffers(page, out);
1646 if (unlikely(err))
1647 return err;
1648 }
1649 return 0;
1650 }
1651
1652 static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
1653 struct page **failed_page)
1654 {
1655 struct nilfs_segment_buffer *segbuf;
1656 struct page *bd_page = NULL, *fs_page = NULL;
1657 struct list_head *list = &sci->sc_copied_buffers;
1658 int err;
1659
1660 *failed_page = NULL;
1661 list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1662 struct buffer_head *bh;
1663
1664 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1665 b_assoc_buffers) {
1666 if (bh->b_page != bd_page) {
1667 if (bd_page) {
1668 lock_page(bd_page);
1669 clear_page_dirty_for_io(bd_page);
1670 set_page_writeback(bd_page);
1671 unlock_page(bd_page);
1672 }
1673 bd_page = bh->b_page;
1674 }
1675 }
1676
1677 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1678 b_assoc_buffers) {
1679 if (bh == segbuf->sb_super_root) {
1680 if (bh->b_page != bd_page) {
1681 lock_page(bd_page);
1682 clear_page_dirty_for_io(bd_page);
1683 set_page_writeback(bd_page);
1684 unlock_page(bd_page);
1685 bd_page = bh->b_page;
1686 }
1687 break;
1688 }
1689 if (bh->b_page != fs_page) {
1690 err = nilfs_begin_page_io(fs_page, list);
1691 if (unlikely(err)) {
1692 *failed_page = fs_page;
1693 goto out;
1694 }
1695 fs_page = bh->b_page;
1696 }
1697 }
1698 }
1699 if (bd_page) {
1700 lock_page(bd_page);
1701 clear_page_dirty_for_io(bd_page);
1702 set_page_writeback(bd_page);
1703 unlock_page(bd_page);
1704 }
1705 err = nilfs_begin_page_io(fs_page, list);
1706 if (unlikely(err))
1707 *failed_page = fs_page;
1708 out:
1709 return err;
1710 }
1711
1712 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1713 struct the_nilfs *nilfs)
1714 {
1715 int ret;
1716
1717 ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1718 list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1719 return ret;
1720 }
1721
1722 static void __nilfs_end_page_io(struct page *page, int err)
1723 {
1724 if (!err) {
1725 if (!nilfs_page_buffers_clean(page))
1726 __set_page_dirty_nobuffers(page);
1727 ClearPageError(page);
1728 } else {
1729 __set_page_dirty_nobuffers(page);
1730 SetPageError(page);
1731 }
1732
1733 if (buffer_nilfs_allocated(page_buffers(page))) {
1734 if (TestClearPageWriteback(page))
1735 dec_zone_page_state(page, NR_WRITEBACK);
1736 } else
1737 end_page_writeback(page);
1738 }
1739
1740 static void nilfs_end_page_io(struct page *page, int err)
1741 {
1742 if (!page)
1743 return;
1744
1745 if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
1746 /*
1747 * For b-tree node pages, this function may be called twice
1748 * or more because they might be split in a segment.
1749 */
1750 if (PageDirty(page)) {
1751 /*
1752 * For pages holding split b-tree node buffers, dirty
1753 * flag on the buffers may be cleared discretely.
1754 * In that case, the page is once redirtied for
1755 * remaining buffers, and it must be cancelled if
1756 * all the buffers get cleaned later.
1757 */
1758 lock_page(page);
1759 if (nilfs_page_buffers_clean(page))
1760 __nilfs_clear_page_dirty(page);
1761 unlock_page(page);
1762 }
1763 return;
1764 }
1765
1766 __nilfs_end_page_io(page, err);
1767 }
1768
1769 static void nilfs_clear_copied_buffers(struct list_head *list, int err)
1770 {
1771 struct buffer_head *bh, *head;
1772 struct page *page;
1773
1774 while (!list_empty(list)) {
1775 bh = list_entry(list->next, struct buffer_head,
1776 b_assoc_buffers);
1777 page = bh->b_page;
1778 page_cache_get(page);
1779 head = bh = page_buffers(page);
1780 do {
1781 if (!list_empty(&bh->b_assoc_buffers)) {
1782 list_del_init(&bh->b_assoc_buffers);
1783 if (!err) {
1784 set_buffer_uptodate(bh);
1785 clear_buffer_dirty(bh);
1786 clear_buffer_nilfs_volatile(bh);
1787 }
1788 brelse(bh); /* for b_assoc_buffers */
1789 }
1790 } while ((bh = bh->b_this_page) != head);
1791
1792 __nilfs_end_page_io(page, err);
1793 page_cache_release(page);
1794 }
1795 }
1796
1797 static void nilfs_abort_logs(struct list_head *logs, struct page *failed_page,
1798 int err)
1799 {
1800 struct nilfs_segment_buffer *segbuf;
1801 struct page *bd_page = NULL, *fs_page = NULL;
1802 struct buffer_head *bh;
1803
1804 if (list_empty(logs))
1805 return;
1806
1807 list_for_each_entry(segbuf, logs, sb_list) {
1808 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1809 b_assoc_buffers) {
1810 if (bh->b_page != bd_page) {
1811 if (bd_page)
1812 end_page_writeback(bd_page);
1813 bd_page = bh->b_page;
1814 }
1815 }
1816
1817 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1818 b_assoc_buffers) {
1819 if (bh == segbuf->sb_super_root) {
1820 if (bh->b_page != bd_page) {
1821 end_page_writeback(bd_page);
1822 bd_page = bh->b_page;
1823 }
1824 break;
1825 }
1826 if (bh->b_page != fs_page) {
1827 nilfs_end_page_io(fs_page, err);
1828 if (fs_page && fs_page == failed_page)
1829 return;
1830 fs_page = bh->b_page;
1831 }
1832 }
1833 }
1834 if (bd_page)
1835 end_page_writeback(bd_page);
1836
1837 nilfs_end_page_io(fs_page, err);
1838 }
1839
1840 static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1841 struct the_nilfs *nilfs, int err)
1842 {
1843 LIST_HEAD(logs);
1844 int ret;
1845
1846 list_splice_tail_init(&sci->sc_write_logs, &logs);
1847 ret = nilfs_wait_on_logs(&logs);
1848 nilfs_abort_logs(&logs, NULL, ret ? : err);
1849
1850 list_splice_tail_init(&sci->sc_segbufs, &logs);
1851 nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1852 nilfs_free_incomplete_logs(&logs, nilfs);
1853 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
1854
1855 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1856 ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1857 sci->sc_freesegs,
1858 sci->sc_nfreesegs,
1859 NULL);
1860 WARN_ON(ret); /* do not happen */
1861 }
1862
1863 nilfs_destroy_logs(&logs);
1864 }
1865
1866 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1867 struct nilfs_segment_buffer *segbuf)
1868 {
1869 nilfs->ns_segnum = segbuf->sb_segnum;
1870 nilfs->ns_nextnum = segbuf->sb_nextnum;
1871 nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1872 + segbuf->sb_sum.nblocks;
1873 nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1874 nilfs->ns_ctime = segbuf->sb_sum.ctime;
1875 }
1876
1877 static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1878 {
1879 struct nilfs_segment_buffer *segbuf;
1880 struct page *bd_page = NULL, *fs_page = NULL;
1881 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
1882 int update_sr = false;
1883
1884 list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1885 struct buffer_head *bh;
1886
1887 list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1888 b_assoc_buffers) {
1889 set_buffer_uptodate(bh);
1890 clear_buffer_dirty(bh);
1891 if (bh->b_page != bd_page) {
1892 if (bd_page)
1893 end_page_writeback(bd_page);
1894 bd_page = bh->b_page;
1895 }
1896 }
1897 /*
1898 * We assume that the buffers which belong to the same page
1899 * continue over the buffer list.
1900 * Under this assumption, the last BHs of pages is
1901 * identifiable by the discontinuity of bh->b_page
1902 * (page != fs_page).
1903 *
1904 * For B-tree node blocks, however, this assumption is not
1905 * guaranteed. The cleanup code of B-tree node pages needs
1906 * special care.
1907 */
1908 list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1909 b_assoc_buffers) {
1910 set_buffer_uptodate(bh);
1911 clear_buffer_dirty(bh);
1912 clear_buffer_nilfs_volatile(bh);
1913 clear_buffer_nilfs_redirected(bh);
1914 if (bh == segbuf->sb_super_root) {
1915 if (bh->b_page != bd_page) {
1916 end_page_writeback(bd_page);
1917 bd_page = bh->b_page;
1918 }
1919 update_sr = true;
1920 break;
1921 }
1922 if (bh->b_page != fs_page) {
1923 nilfs_end_page_io(fs_page, 0);
1924 fs_page = bh->b_page;
1925 }
1926 }
1927
1928 if (!nilfs_segbuf_simplex(segbuf)) {
1929 if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1930 set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1931 sci->sc_lseg_stime = jiffies;
1932 }
1933 if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1934 clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1935 }
1936 }
1937 /*
1938 * Since pages may continue over multiple segment buffers,
1939 * end of the last page must be checked outside of the loop.
1940 */
1941 if (bd_page)
1942 end_page_writeback(bd_page);
1943
1944 nilfs_end_page_io(fs_page, 0);
1945
1946 nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0);
1947
1948 nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1949
1950 if (nilfs_doing_gc())
1951 nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1952 else
1953 nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1954
1955 sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1956
1957 segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1958 nilfs_set_next_segment(nilfs, segbuf);
1959
1960 if (update_sr) {
1961 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1962 segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1963
1964 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1965 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1966 set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1967 nilfs_segctor_clear_metadata_dirty(sci);
1968 } else
1969 clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1970 }
1971
1972 static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1973 {
1974 int ret;
1975
1976 ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1977 if (!ret) {
1978 nilfs_segctor_complete_write(sci);
1979 nilfs_destroy_logs(&sci->sc_write_logs);
1980 }
1981 return ret;
1982 }
1983
1984 static int nilfs_segctor_check_in_files(struct nilfs_sc_info *sci,
1985 struct nilfs_sb_info *sbi)
1986 {
1987 struct nilfs_inode_info *ii, *n;
1988 struct inode *ifile = sci->sc_root->ifile;
1989
1990 spin_lock(&sbi->s_inode_lock);
1991 retry:
1992 list_for_each_entry_safe(ii, n, &sbi->s_dirty_files, i_dirty) {
1993 if (!ii->i_bh) {
1994 struct buffer_head *ibh;
1995 int err;
1996
1997 spin_unlock(&sbi->s_inode_lock);
1998 err = nilfs_ifile_get_inode_block(
1999 ifile, ii->vfs_inode.i_ino, &ibh);
2000 if (unlikely(err)) {
2001 nilfs_warning(sbi->s_super, __func__,
2002 "failed to get inode block.\n");
2003 return err;
2004 }
2005 nilfs_mdt_mark_buffer_dirty(ibh);
2006 nilfs_mdt_mark_dirty(ifile);
2007 spin_lock(&sbi->s_inode_lock);
2008 if (likely(!ii->i_bh))
2009 ii->i_bh = ibh;
2010 else
2011 brelse(ibh);
2012 goto retry;
2013 }
2014
2015 clear_bit(NILFS_I_QUEUED, &ii->i_state);
2016 set_bit(NILFS_I_BUSY, &ii->i_state);
2017 list_del(&ii->i_dirty);
2018 list_add_tail(&ii->i_dirty, &sci->sc_dirty_files);
2019 }
2020 spin_unlock(&sbi->s_inode_lock);
2021
2022 return 0;
2023 }
2024
2025 static void nilfs_segctor_check_out_files(struct nilfs_sc_info *sci,
2026 struct nilfs_sb_info *sbi)
2027 {
2028 struct nilfs_transaction_info *ti = current->journal_info;
2029 struct nilfs_inode_info *ii, *n;
2030
2031 spin_lock(&sbi->s_inode_lock);
2032 list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
2033 if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
2034 test_bit(NILFS_I_DIRTY, &ii->i_state))
2035 continue;
2036
2037 clear_bit(NILFS_I_BUSY, &ii->i_state);
2038 brelse(ii->i_bh);
2039 ii->i_bh = NULL;
2040 list_del(&ii->i_dirty);
2041 list_add_tail(&ii->i_dirty, &ti->ti_garbage);
2042 }
2043 spin_unlock(&sbi->s_inode_lock);
2044 }
2045
2046 /*
2047 * Main procedure of segment constructor
2048 */
2049 static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2050 {
2051 struct nilfs_sb_info *sbi = sci->sc_sbi;
2052 struct the_nilfs *nilfs = sbi->s_nilfs;
2053 struct page *failed_page;
2054 int err;
2055
2056 sci->sc_stage.scnt = NILFS_ST_INIT;
2057 sci->sc_cno = nilfs->ns_cno;
2058
2059 err = nilfs_segctor_check_in_files(sci, sbi);
2060 if (unlikely(err))
2061 goto out;
2062
2063 if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
2064 set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2065
2066 if (nilfs_segctor_clean(sci))
2067 goto out;
2068
2069 do {
2070 sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2071
2072 err = nilfs_segctor_begin_construction(sci, nilfs);
2073 if (unlikely(err))
2074 goto out;
2075
2076 /* Update time stamp */
2077 sci->sc_seg_ctime = get_seconds();
2078
2079 err = nilfs_segctor_collect(sci, nilfs, mode);
2080 if (unlikely(err))
2081 goto failed;
2082
2083 /* Avoid empty segment */
2084 if (sci->sc_stage.scnt == NILFS_ST_DONE &&
2085 nilfs_segbuf_empty(sci->sc_curseg)) {
2086 nilfs_segctor_abort_construction(sci, nilfs, 1);
2087 goto out;
2088 }
2089
2090 err = nilfs_segctor_assign(sci, mode);
2091 if (unlikely(err))
2092 goto failed;
2093
2094 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2095 nilfs_segctor_fill_in_file_bmap(sci);
2096
2097 if (mode == SC_LSEG_SR &&
2098 sci->sc_stage.scnt >= NILFS_ST_CPFILE) {
2099 err = nilfs_segctor_fill_in_checkpoint(sci);
2100 if (unlikely(err))
2101 goto failed_to_write;
2102
2103 nilfs_segctor_fill_in_super_root(sci, nilfs);
2104 }
2105 nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2106
2107 /* Write partial segments */
2108 err = nilfs_segctor_prepare_write(sci, &failed_page);
2109 if (err) {
2110 nilfs_abort_logs(&sci->sc_segbufs, failed_page, err);
2111 goto failed_to_write;
2112 }
2113
2114 nilfs_add_checksums_on_logs(&sci->sc_segbufs,
2115 nilfs->ns_crc_seed);
2116
2117 err = nilfs_segctor_write(sci, nilfs);
2118 if (unlikely(err))
2119 goto failed_to_write;
2120
2121 if (sci->sc_stage.scnt == NILFS_ST_DONE ||
2122 nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
2123 /*
2124 * At this point, we avoid double buffering
2125 * for blocksize < pagesize because page dirty
2126 * flag is turned off during write and dirty
2127 * buffers are not properly collected for
2128 * pages crossing over segments.
2129 */
2130 err = nilfs_segctor_wait(sci);
2131 if (err)
2132 goto failed_to_write;
2133 }
2134 } while (sci->sc_stage.scnt != NILFS_ST_DONE);
2135
2136 out:
2137 nilfs_segctor_check_out_files(sci, sbi);
2138 return err;
2139
2140 failed_to_write:
2141 if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2142 nilfs_redirty_inodes(&sci->sc_dirty_files);
2143
2144 failed:
2145 if (nilfs_doing_gc())
2146 nilfs_redirty_inodes(&sci->sc_gc_inodes);
2147 nilfs_segctor_abort_construction(sci, nilfs, err);
2148 goto out;
2149 }
2150
2151 /**
2152 * nilfs_segctor_start_timer - set timer of background write
2153 * @sci: nilfs_sc_info
2154 *
2155 * If the timer has already been set, it ignores the new request.
2156 * This function MUST be called within a section locking the segment
2157 * semaphore.
2158 */
2159 static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2160 {
2161 spin_lock(&sci->sc_state_lock);
2162 if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2163 sci->sc_timer.expires = jiffies + sci->sc_interval;
2164 add_timer(&sci->sc_timer);
2165 sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2166 }
2167 spin_unlock(&sci->sc_state_lock);
2168 }
2169
2170 static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2171 {
2172 spin_lock(&sci->sc_state_lock);
2173 if (!(sci->sc_flush_request & (1 << bn))) {
2174 unsigned long prev_req = sci->sc_flush_request;
2175
2176 sci->sc_flush_request |= (1 << bn);
2177 if (!prev_req)
2178 wake_up(&sci->sc_wait_daemon);
2179 }
2180 spin_unlock(&sci->sc_state_lock);
2181 }
2182
2183 /**
2184 * nilfs_flush_segment - trigger a segment construction for resource control
2185 * @sb: super block
2186 * @ino: inode number of the file to be flushed out.
2187 */
2188 void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2189 {
2190 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2191 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2192
2193 if (!sci || nilfs_doing_construction())
2194 return;
2195 nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2196 /* assign bit 0 to data files */
2197 }
2198
2199 struct nilfs_segctor_wait_request {
2200 wait_queue_t wq;
2201 __u32 seq;
2202 int err;
2203 atomic_t done;
2204 };
2205
2206 static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2207 {
2208 struct nilfs_segctor_wait_request wait_req;
2209 int err = 0;
2210
2211 spin_lock(&sci->sc_state_lock);
2212 init_wait(&wait_req.wq);
2213 wait_req.err = 0;
2214 atomic_set(&wait_req.done, 0);
2215 wait_req.seq = ++sci->sc_seq_request;
2216 spin_unlock(&sci->sc_state_lock);
2217
2218 init_waitqueue_entry(&wait_req.wq, current);
2219 add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2220 set_current_state(TASK_INTERRUPTIBLE);
2221 wake_up(&sci->sc_wait_daemon);
2222
2223 for (;;) {
2224 if (atomic_read(&wait_req.done)) {
2225 err = wait_req.err;
2226 break;
2227 }
2228 if (!signal_pending(current)) {
2229 schedule();
2230 continue;
2231 }
2232 err = -ERESTARTSYS;
2233 break;
2234 }
2235 finish_wait(&sci->sc_wait_request, &wait_req.wq);
2236 return err;
2237 }
2238
2239 static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2240 {
2241 struct nilfs_segctor_wait_request *wrq, *n;
2242 unsigned long flags;
2243
2244 spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2245 list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2246 wq.task_list) {
2247 if (!atomic_read(&wrq->done) &&
2248 nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2249 wrq->err = err;
2250 atomic_set(&wrq->done, 1);
2251 }
2252 if (atomic_read(&wrq->done)) {
2253 wrq->wq.func(&wrq->wq,
2254 TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2255 0, NULL);
2256 }
2257 }
2258 spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2259 }
2260
2261 /**
2262 * nilfs_construct_segment - construct a logical segment
2263 * @sb: super block
2264 *
2265 * Return Value: On success, 0 is retured. On errors, one of the following
2266 * negative error code is returned.
2267 *
2268 * %-EROFS - Read only filesystem.
2269 *
2270 * %-EIO - I/O error
2271 *
2272 * %-ENOSPC - No space left on device (only in a panic state).
2273 *
2274 * %-ERESTARTSYS - Interrupted.
2275 *
2276 * %-ENOMEM - Insufficient memory available.
2277 */
2278 int nilfs_construct_segment(struct super_block *sb)
2279 {
2280 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2281 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2282 struct nilfs_transaction_info *ti;
2283 int err;
2284
2285 if (!sci)
2286 return -EROFS;
2287
2288 /* A call inside transactions causes a deadlock. */
2289 BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2290
2291 err = nilfs_segctor_sync(sci);
2292 return err;
2293 }
2294
2295 /**
2296 * nilfs_construct_dsync_segment - construct a data-only logical segment
2297 * @sb: super block
2298 * @inode: inode whose data blocks should be written out
2299 * @start: start byte offset
2300 * @end: end byte offset (inclusive)
2301 *
2302 * Return Value: On success, 0 is retured. On errors, one of the following
2303 * negative error code is returned.
2304 *
2305 * %-EROFS - Read only filesystem.
2306 *
2307 * %-EIO - I/O error
2308 *
2309 * %-ENOSPC - No space left on device (only in a panic state).
2310 *
2311 * %-ERESTARTSYS - Interrupted.
2312 *
2313 * %-ENOMEM - Insufficient memory available.
2314 */
2315 int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2316 loff_t start, loff_t end)
2317 {
2318 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2319 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2320 struct nilfs_inode_info *ii;
2321 struct nilfs_transaction_info ti;
2322 int err = 0;
2323
2324 if (!sci)
2325 return -EROFS;
2326
2327 nilfs_transaction_lock(sbi, &ti, 0);
2328
2329 ii = NILFS_I(inode);
2330 if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2331 nilfs_test_opt(sbi, STRICT_ORDER) ||
2332 test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2333 nilfs_discontinued(sbi->s_nilfs)) {
2334 nilfs_transaction_unlock(sbi);
2335 err = nilfs_segctor_sync(sci);
2336 return err;
2337 }
2338
2339 spin_lock(&sbi->s_inode_lock);
2340 if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2341 !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2342 spin_unlock(&sbi->s_inode_lock);
2343 nilfs_transaction_unlock(sbi);
2344 return 0;
2345 }
2346 spin_unlock(&sbi->s_inode_lock);
2347 sci->sc_dsync_inode = ii;
2348 sci->sc_dsync_start = start;
2349 sci->sc_dsync_end = end;
2350
2351 err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2352
2353 nilfs_transaction_unlock(sbi);
2354 return err;
2355 }
2356
2357 #define FLUSH_FILE_BIT (0x1) /* data file only */
2358 #define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
2359
2360 /**
2361 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2362 * @sci: segment constructor object
2363 */
2364 static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2365 {
2366 spin_lock(&sci->sc_state_lock);
2367 sci->sc_seq_accepted = sci->sc_seq_request;
2368 spin_unlock(&sci->sc_state_lock);
2369 del_timer_sync(&sci->sc_timer);
2370 }
2371
2372 /**
2373 * nilfs_segctor_notify - notify the result of request to caller threads
2374 * @sci: segment constructor object
2375 * @mode: mode of log forming
2376 * @err: error code to be notified
2377 */
2378 static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2379 {
2380 /* Clear requests (even when the construction failed) */
2381 spin_lock(&sci->sc_state_lock);
2382
2383 if (mode == SC_LSEG_SR) {
2384 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2385 sci->sc_seq_done = sci->sc_seq_accepted;
2386 nilfs_segctor_wakeup(sci, err);
2387 sci->sc_flush_request = 0;
2388 } else {
2389 if (mode == SC_FLUSH_FILE)
2390 sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2391 else if (mode == SC_FLUSH_DAT)
2392 sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2393
2394 /* re-enable timer if checkpoint creation was not done */
2395 if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2396 time_before(jiffies, sci->sc_timer.expires))
2397 add_timer(&sci->sc_timer);
2398 }
2399 spin_unlock(&sci->sc_state_lock);
2400 }
2401
2402 /**
2403 * nilfs_segctor_construct - form logs and write them to disk
2404 * @sci: segment constructor object
2405 * @mode: mode of log forming
2406 */
2407 static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2408 {
2409 struct nilfs_sb_info *sbi = sci->sc_sbi;
2410 struct the_nilfs *nilfs = sbi->s_nilfs;
2411 struct nilfs_super_block **sbp;
2412 int err = 0;
2413
2414 nilfs_segctor_accept(sci);
2415
2416 if (nilfs_discontinued(nilfs))
2417 mode = SC_LSEG_SR;
2418 if (!nilfs_segctor_confirm(sci))
2419 err = nilfs_segctor_do_construct(sci, mode);
2420
2421 if (likely(!err)) {
2422 if (mode != SC_FLUSH_DAT)
2423 atomic_set(&nilfs->ns_ndirtyblks, 0);
2424 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2425 nilfs_discontinued(nilfs)) {
2426 down_write(&nilfs->ns_sem);
2427 err = -EIO;
2428 sbp = nilfs_prepare_super(sbi,
2429 nilfs_sb_will_flip(nilfs));
2430 if (likely(sbp)) {
2431 nilfs_set_log_cursor(sbp[0], nilfs);
2432 err = nilfs_commit_super(sbi, NILFS_SB_COMMIT);
2433 }
2434 up_write(&nilfs->ns_sem);
2435 }
2436 }
2437
2438 nilfs_segctor_notify(sci, mode, err);
2439 return err;
2440 }
2441
2442 static void nilfs_construction_timeout(unsigned long data)
2443 {
2444 struct task_struct *p = (struct task_struct *)data;
2445 wake_up_process(p);
2446 }
2447
2448 static void
2449 nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2450 {
2451 struct nilfs_inode_info *ii, *n;
2452
2453 list_for_each_entry_safe(ii, n, head, i_dirty) {
2454 if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2455 continue;
2456 list_del_init(&ii->i_dirty);
2457 iput(&ii->vfs_inode);
2458 }
2459 }
2460
2461 int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2462 void **kbufs)
2463 {
2464 struct nilfs_sb_info *sbi = NILFS_SB(sb);
2465 struct nilfs_sc_info *sci = NILFS_SC(sbi);
2466 struct the_nilfs *nilfs = sbi->s_nilfs;
2467 struct nilfs_transaction_info ti;
2468 int err;
2469
2470 if (unlikely(!sci))
2471 return -EROFS;
2472
2473 nilfs_transaction_lock(sbi, &ti, 1);
2474
2475 err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2476 if (unlikely(err))
2477 goto out_unlock;
2478
2479 err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2480 if (unlikely(err)) {
2481 nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2482 goto out_unlock;
2483 }
2484
2485 sci->sc_freesegs = kbufs[4];
2486 sci->sc_nfreesegs = argv[4].v_nmembs;
2487 list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2488
2489 for (;;) {
2490 err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2491 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2492
2493 if (likely(!err))
2494 break;
2495
2496 nilfs_warning(sb, __func__,
2497 "segment construction failed. (err=%d)", err);
2498 set_current_state(TASK_INTERRUPTIBLE);
2499 schedule_timeout(sci->sc_interval);
2500 }
2501 if (nilfs_test_opt(sbi, DISCARD)) {
2502 int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2503 sci->sc_nfreesegs);
2504 if (ret) {
2505 printk(KERN_WARNING
2506 "NILFS warning: error %d on discard request, "
2507 "turning discards off for the device\n", ret);
2508 nilfs_clear_opt(sbi, DISCARD);
2509 }
2510 }
2511
2512 out_unlock:
2513 sci->sc_freesegs = NULL;
2514 sci->sc_nfreesegs = 0;
2515 nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2516 nilfs_transaction_unlock(sbi);
2517 return err;
2518 }
2519
2520 static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2521 {
2522 struct nilfs_sb_info *sbi = sci->sc_sbi;
2523 struct nilfs_transaction_info ti;
2524
2525 nilfs_transaction_lock(sbi, &ti, 0);
2526 nilfs_segctor_construct(sci, mode);
2527
2528 /*
2529 * Unclosed segment should be retried. We do this using sc_timer.
2530 * Timeout of sc_timer will invoke complete construction which leads
2531 * to close the current logical segment.
2532 */
2533 if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2534 nilfs_segctor_start_timer(sci);
2535
2536 nilfs_transaction_unlock(sbi);
2537 }
2538
2539 static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2540 {
2541 int mode = 0;
2542 int err;
2543
2544 spin_lock(&sci->sc_state_lock);
2545 mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2546 SC_FLUSH_DAT : SC_FLUSH_FILE;
2547 spin_unlock(&sci->sc_state_lock);
2548
2549 if (mode) {
2550 err = nilfs_segctor_do_construct(sci, mode);
2551
2552 spin_lock(&sci->sc_state_lock);
2553 sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2554 ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2555 spin_unlock(&sci->sc_state_lock);
2556 }
2557 clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2558 }
2559
2560 static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2561 {
2562 if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2563 time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2564 if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2565 return SC_FLUSH_FILE;
2566 else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2567 return SC_FLUSH_DAT;
2568 }
2569 return SC_LSEG_SR;
2570 }
2571
2572 /**
2573 * nilfs_segctor_thread - main loop of the segment constructor thread.
2574 * @arg: pointer to a struct nilfs_sc_info.
2575 *
2576 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2577 * to execute segment constructions.
2578 */
2579 static int nilfs_segctor_thread(void *arg)
2580 {
2581 struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2582 struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
2583 int timeout = 0;
2584
2585 sci->sc_timer.data = (unsigned long)current;
2586 sci->sc_timer.function = nilfs_construction_timeout;
2587
2588 /* start sync. */
2589 sci->sc_task = current;
2590 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2591 printk(KERN_INFO
2592 "segctord starting. Construction interval = %lu seconds, "
2593 "CP frequency < %lu seconds\n",
2594 sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2595
2596 spin_lock(&sci->sc_state_lock);
2597 loop:
2598 for (;;) {
2599 int mode;
2600
2601 if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2602 goto end_thread;
2603
2604 if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2605 mode = SC_LSEG_SR;
2606 else if (!sci->sc_flush_request)
2607 break;
2608 else
2609 mode = nilfs_segctor_flush_mode(sci);
2610
2611 spin_unlock(&sci->sc_state_lock);
2612 nilfs_segctor_thread_construct(sci, mode);
2613 spin_lock(&sci->sc_state_lock);
2614 timeout = 0;
2615 }
2616
2617
2618 if (freezing(current)) {
2619 spin_unlock(&sci->sc_state_lock);
2620 refrigerator();
2621 spin_lock(&sci->sc_state_lock);
2622 } else {
2623 DEFINE_WAIT(wait);
2624 int should_sleep = 1;
2625
2626 prepare_to_wait(&sci->sc_wait_daemon, &wait,
2627 TASK_INTERRUPTIBLE);
2628
2629 if (sci->sc_seq_request != sci->sc_seq_done)
2630 should_sleep = 0;
2631 else if (sci->sc_flush_request)
2632 should_sleep = 0;
2633 else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2634 should_sleep = time_before(jiffies,
2635 sci->sc_timer.expires);
2636
2637 if (should_sleep) {
2638 spin_unlock(&sci->sc_state_lock);
2639 schedule();
2640 spin_lock(&sci->sc_state_lock);
2641 }
2642 finish_wait(&sci->sc_wait_daemon, &wait);
2643 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2644 time_after_eq(jiffies, sci->sc_timer.expires));
2645
2646 if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2647 set_nilfs_discontinued(nilfs);
2648 }
2649 goto loop;
2650
2651 end_thread:
2652 spin_unlock(&sci->sc_state_lock);
2653
2654 /* end sync. */
2655 sci->sc_task = NULL;
2656 wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2657 return 0;
2658 }
2659
2660 static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2661 {
2662 struct task_struct *t;
2663
2664 t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2665 if (IS_ERR(t)) {
2666 int err = PTR_ERR(t);
2667
2668 printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2669 err);
2670 return err;
2671 }
2672 wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2673 return 0;
2674 }
2675
2676 static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2677 __acquires(&sci->sc_state_lock)
2678 __releases(&sci->sc_state_lock)
2679 {
2680 sci->sc_state |= NILFS_SEGCTOR_QUIT;
2681
2682 while (sci->sc_task) {
2683 wake_up(&sci->sc_wait_daemon);
2684 spin_unlock(&sci->sc_state_lock);
2685 wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2686 spin_lock(&sci->sc_state_lock);
2687 }
2688 }
2689
2690 /*
2691 * Setup & clean-up functions
2692 */
2693 static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi,
2694 struct nilfs_root *root)
2695 {
2696 struct nilfs_sc_info *sci;
2697
2698 sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2699 if (!sci)
2700 return NULL;
2701
2702 sci->sc_sbi = sbi;
2703 sci->sc_super = sbi->s_super;
2704
2705 nilfs_get_root(root);
2706 sci->sc_root = root;
2707
2708 init_waitqueue_head(&sci->sc_wait_request);
2709 init_waitqueue_head(&sci->sc_wait_daemon);
2710 init_waitqueue_head(&sci->sc_wait_task);
2711 spin_lock_init(&sci->sc_state_lock);
2712 INIT_LIST_HEAD(&sci->sc_dirty_files);
2713 INIT_LIST_HEAD(&sci->sc_segbufs);
2714 INIT_LIST_HEAD(&sci->sc_write_logs);
2715 INIT_LIST_HEAD(&sci->sc_gc_inodes);
2716 INIT_LIST_HEAD(&sci->sc_copied_buffers);
2717 init_timer(&sci->sc_timer);
2718
2719 sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2720 sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2721 sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2722
2723 if (sbi->s_interval)
2724 sci->sc_interval = sbi->s_interval;
2725 if (sbi->s_watermark)
2726 sci->sc_watermark = sbi->s_watermark;
2727 return sci;
2728 }
2729
2730 static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2731 {
2732 int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2733
2734 /* The segctord thread was stopped and its timer was removed.
2735 But some tasks remain. */
2736 do {
2737 struct nilfs_sb_info *sbi = sci->sc_sbi;
2738 struct nilfs_transaction_info ti;
2739
2740 nilfs_transaction_lock(sbi, &ti, 0);
2741 ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2742 nilfs_transaction_unlock(sbi);
2743
2744 } while (ret && retrycount-- > 0);
2745 }
2746
2747 /**
2748 * nilfs_segctor_destroy - destroy the segment constructor.
2749 * @sci: nilfs_sc_info
2750 *
2751 * nilfs_segctor_destroy() kills the segctord thread and frees
2752 * the nilfs_sc_info struct.
2753 * Caller must hold the segment semaphore.
2754 */
2755 static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2756 {
2757 struct nilfs_sb_info *sbi = sci->sc_sbi;
2758 int flag;
2759
2760 up_write(&sbi->s_nilfs->ns_segctor_sem);
2761
2762 spin_lock(&sci->sc_state_lock);
2763 nilfs_segctor_kill_thread(sci);
2764 flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2765 || sci->sc_seq_request != sci->sc_seq_done);
2766 spin_unlock(&sci->sc_state_lock);
2767
2768 if (flag || !nilfs_segctor_confirm(sci))
2769 nilfs_segctor_write_out(sci);
2770
2771 WARN_ON(!list_empty(&sci->sc_copied_buffers));
2772
2773 if (!list_empty(&sci->sc_dirty_files)) {
2774 nilfs_warning(sbi->s_super, __func__,
2775 "dirty file(s) after the final construction\n");
2776 nilfs_dispose_list(sbi, &sci->sc_dirty_files, 1);
2777 }
2778
2779 WARN_ON(!list_empty(&sci->sc_segbufs));
2780 WARN_ON(!list_empty(&sci->sc_write_logs));
2781
2782 nilfs_put_root(sci->sc_root);
2783
2784 down_write(&sbi->s_nilfs->ns_segctor_sem);
2785
2786 del_timer_sync(&sci->sc_timer);
2787 kfree(sci);
2788 }
2789
2790 /**
2791 * nilfs_attach_segment_constructor - attach a segment constructor
2792 * @sbi: nilfs_sb_info
2793 * @root: root object of the current filesystem tree
2794 *
2795 * nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info,
2796 * initializes it, and starts the segment constructor.
2797 *
2798 * Return Value: On success, 0 is returned. On error, one of the following
2799 * negative error code is returned.
2800 *
2801 * %-ENOMEM - Insufficient memory available.
2802 */
2803 int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi,
2804 struct nilfs_root *root)
2805 {
2806 int err;
2807
2808 if (NILFS_SC(sbi)) {
2809 /*
2810 * This happens if the filesystem was remounted
2811 * read/write after nilfs_error degenerated it into a
2812 * read-only mount.
2813 */
2814 nilfs_detach_segment_constructor(sbi);
2815 }
2816
2817 sbi->s_sc_info = nilfs_segctor_new(sbi, root);
2818 if (!sbi->s_sc_info)
2819 return -ENOMEM;
2820
2821 err = nilfs_segctor_start_thread(NILFS_SC(sbi));
2822 if (err) {
2823 kfree(sbi->s_sc_info);
2824 sbi->s_sc_info = NULL;
2825 }
2826 return err;
2827 }
2828
2829 /**
2830 * nilfs_detach_segment_constructor - destroy the segment constructor
2831 * @sbi: nilfs_sb_info
2832 *
2833 * nilfs_detach_segment_constructor() kills the segment constructor daemon,
2834 * frees the struct nilfs_sc_info, and destroy the dirty file list.
2835 */
2836 void nilfs_detach_segment_constructor(struct nilfs_sb_info *sbi)
2837 {
2838 struct the_nilfs *nilfs = sbi->s_nilfs;
2839 LIST_HEAD(garbage_list);
2840
2841 down_write(&nilfs->ns_segctor_sem);
2842 if (NILFS_SC(sbi)) {
2843 nilfs_segctor_destroy(NILFS_SC(sbi));
2844 sbi->s_sc_info = NULL;
2845 }
2846
2847 /* Force to free the list of dirty files */
2848 spin_lock(&sbi->s_inode_lock);
2849 if (!list_empty(&sbi->s_dirty_files)) {
2850 list_splice_init(&sbi->s_dirty_files, &garbage_list);
2851 nilfs_warning(sbi->s_super, __func__,
2852 "Non empty dirty list after the last "
2853 "segment construction\n");
2854 }
2855 spin_unlock(&sbi->s_inode_lock);
2856 up_write(&nilfs->ns_segctor_sem);
2857
2858 nilfs_dispose_list(sbi, &garbage_list, 1);
2859 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree